Question: Solve for $x$ : $7x + 9 = 3x + 5$
Solution: Subtract $3x$ from both sides: $(7x + 9) - 3x = (3x + 5) - 3x$ $4x + 9 = 5$ Subtract $9$ from both sides: $(4x + 9) - 9 = 5 - 9$ $4x = -4$ Divide both sides by $4$ $\frac{4x}{4} = \frac{-4}{4}$ Simplify. $x = -1$